GTM Motorsports Oil Cooler

Modshack · 09-12-2009, 10:36 AM

Quote:

Originally Posted by Denny McLain

You may be right regarding the trigger that shuts down timing may be intake temps or 5 degrees of variance just doesn't make much a difference. Now I did see -2 degrees logging a 184 degree run vs 206 degree run but that may be coincidence as I'm sure the intake/oil temps were also different.

Yeah....Hard to tell what the trigger is on the Nissan ECU. On the Vette (LS3) it's easy to see (and also easy to change the values with software like HP tuners). As I recall from my Vette logs there was no Water temp related timing pull until temps exceeded 235 or so....

On my Fang vents, it should be easy to route the hoses to the G3 filters instead of into the Radiator brace as i did...

As you can see from this chart, there is no reference or scaling to ambient, so over 86 degrees IAT you're hosed no matter what unless you make a software change. I recall I had shifted the table a column to the right...(time to move north!)
IAT temps and timing pull:

Denny McLain · 09-12-2009, 01:17 PM

[QUOTE=Modshack;195627]Yeah....Hard to tell what the trigger is on the Nissan ECU. On the Vette (LS3) it's easy to see (and also easy to change the values with software like HP tuners). As I recall from my Vette logs there was no Water temp related timing pull until temps exceeded 235 or so....
QUOTE]

Both Lt1.edit and HP Tuners (Expecially HP Tuners) is light years ahead of what Cobb is ofering in capability to get into the computer. Was pretty shocked when I couldn't find something as simple as anything to effect the onset of fans. At least for the most part the oil cooler should take oil temps out of the equation.

Hopefully the capabilities wil change, but for my C4 there are water temp tables you can play with that for sure enrichens the fuel and would have to look if there are tables that effect timing. Think so.

It's a moot point but my problem is I changed out computers and need to reload the tuning software to take a peek at all it really does.

Modshack · 09-12-2009, 02:16 PM

Understand...When I saw how limited the Cobb was I decided that was $6-700 I didn't need to spend...at least now.

I've been tuning my A/F ratios with changes in my MAF tube diameters. I think I have it pretty much set now...Long term fuel trims are still at "0" correction after almost 200 miles..

Denny McLain · 09-13-2009, 07:58 AM

[QUOTE=Modshack;195852]Understand...When I saw how limited the Cobb was I decided that was $6-700 I didn't need to spend...at least now.

I've been tuning my A/F ratios with changes in my MAF tube diameters. I think I have it pretty much set now...Long term fuel trims are still at "0" correction after almost 200 miles..

QUOTE]

Very interesting concept however an issue I see is the factory fuel curve is not linear. The same progression on every wideband readout I've seen. The cars are leaner at lower rpm getting progressively richer at higher rpm's.

Mine's pulling out additional timing beginning right at 5000 rpm (as low as 17 and 18 degrees timing) which is killing the torque peak. In looking at the dyno wideband readouts, Cobbs AFR readouts (which aren't accurate btw), discussing this with Calvin At Cobb whom originally tuned the car, it appears the car might be a little lean under 5000 rpm which may be causing it to pull timing. It also might be the temps? Added fuel under 5000 and pulled some over 7000. (which shows 25-27 degrees of timing depending upon the temps) To do true fine tuning, you need to get into the MAF tables and hone on specific rpm's with the Cobb software as the fuel tables are pretty course.

Biggest tuning issue and something I've never run into is when you make changes to AFR, you see it on the 02 readouts, but the car does not immediately respond on the dyno. This is a tremendous source of frustration as it's a place I've never been before, don't know why or what to do about it.

Modshack · 09-13-2009, 10:54 AM

Quote:

Originally Posted by Denny McLain

Very interesting concept however an issue I see is the factory fuel curve is not linear. The same progression on every wideband readout I've seen. The cars are leaner at lower rpm getting progressively richer at higher rpm's.

Doesn't seem to be an issue. At WOT (open loop) the fueling is all handled by built in Maps and not the MAF and O2 anyway. Since every plot I've seen here even with mods seems to be a bit rich, more air from the slightly larger MAF (2.41"ID up from 2.33"ID) simply creates a parallel A/F plot slightly leaner. The car runs like a bear under all conditions though i will do a Dyno at some point to confirm..BTW, I suspect this is one of the factors that accounts for some CAI's making the power gains they are..

I've been building larger MAF tubes for Audi Turbo's for 7-8 years now and tuning to long term trims. 400 out there and we haven't blown one up yet!

Prior to the Mods the Long term trims would show a -15% correction (rich). Going to WOT these corrections are added to the built in maps resulting in a relatively fat A/F which the plots I've seen verify. Starting with Zero correction, the WOT maps are not modified from their original tune, car runs a bit leaner, and makes more power. Works for me anyway..

Denny McLain · 09-13-2009, 04:42 PM

Works for everybody. Adding high flow cats leaned mine some also.

Again, something I've not played with as I've gotten away from ported or Billet MAF's after finding out most of the local tuners preferred the stock MAF's. Certainly something to digest and think about.

Speaking of something to think about and digesting.... Yesterday again checked intake temps on pretty much a standard stop and go route (to my health club to workout) taking the back way to avoid as much traffic as possible. About four or five lights, depends upon luck on how you hit them, however with a few stop signs in the interim. Key is standard route.

The intake temps basically ran 12 degrees over ambient going down to about 10 during open throttle in 72 degree ambient and some light rain. This was 4 degrees hotter than the day before. Same route, slightly different conditions.????

OK....rainy days, Sundays, and high temps gets me down.

Air dirverter picture by dennylmclain - Photobucket

Small air diverter pop-riveted to underneath bumper. (Way to small, just trying be conservative)

Sections removed from bumper picture by dennylmclain - Photobucket

Removed bumper and removed two 2.5" thick sections directly below the filters.

3/4" of opening removed picture by dennylmclain - Photobucket

Removed 3/4" of the rear area of the openings creating a gap. (top three middle sections of the front facade)

Open front access to filters picture by dennylmclain - Photobucket

A good two inch thick and six inch wide straight shot to the filters so they don't have to pull air from behind and the fans pull air to them.

Who would know? picture by dennylmclain - Photobucket

Looks untouched. What happens in Vegas, stays in Vegas and now you know how the magic trick is done.

Same route, same conditions as yesterday: The car drove 7 degrees over ambient going down to 4-5 degrees during open throttle. 20 minute drive to health club, 187 water temps and let the car idle for 3-4 minutes. The most it got up to was 93 degree intake temp or 21 over ambient.

On the way home after a 45-50 minute workout: 93 degree initial intake temp, went down to 82 driving temp within a mile and 80 WOT. Went to 8 and 6 over by the time I made it home with hot engine.

Simpler for me than routing tubing and seems to help some. Next move is a larger air diverter and isolating the rear of the filters some from the radiator.

Modshack · 09-13-2009, 05:09 PM

Quote:

Originally Posted by Denny McLain

On the way home after a 45-50 minute workout: 93 degree initial intake temp, went down to 82 driving temp within a mile and 80 WOT. Went to 8 and 6 over by the time I made it home with hot engine.

Simpler for me than routing tubing and seems to help some. Next move is a larger air diverter and isolating the rear of the filters some from the radiator.

Seems to take a while to clear a hot engine bay...One trick you may try is to pop the rubber seals off the back of the engine compartment where the plastic seals to the hood. The long one to the rear and the two shorter ones just forward of that. This encourages air flow through the back of the engine compartment (high pressure area at the base of the windshield). Remove the plastic part at the strut brace triangle for even more flow (2 push pins and it snaps out). I've datalogged this on other cars and found an 18 degree reduction in engine compartment temps (on a turbo). It's a cheap and easy cooling trick...

09-12-2009, 01:17 PM	#2 (permalink)
Denny McLain Enthusiast Member Join Date: Feb 2009 Location: Double Oak Tx Posts: 255 Drives: 370Z, 96CE hotrod Rep Power: 18	[QUOTE=Modshack;195627]Yeah....Hard to tell what the trigger is on the Nissan ECU. On the Vette (LS3) it's easy to see (and also easy to change the values with software like HP tuners). As I recall from my Vette logs there was no Water temp related timing pull until temps exceeded 235 or so.... QUOTE] Both Lt1.edit and HP Tuners (Expecially HP Tuners) is light years ahead of what Cobb is ofering in capability to get into the computer. Was pretty shocked when I couldn't find something as simple as anything to effect the onset of fans. At least for the most part the oil cooler should take oil temps out of the equation. Hopefully the capabilities wil change, but for my C4 there are water temp tables you can play with that for sure enrichens the fuel and would have to look if there are tables that effect timing. Think so. It's a moot point but my problem is I changed out computers and need to reload the tuning software to take a peek at all it really does. Last edited by Denny McLain; 09-13-2009 at 07:22 AM.

09-12-2009, 02:16 PM	#3 (permalink)
Modshack A True Z Fanatic Join Date: Mar 2009 Location: Greenville NC Posts: 2,883 Drives: 370Z Sport Rep Power: 978	Understand...When I saw how limited the Cobb was I decided that was $6-700 I didn't need to spend...at least now. I've been tuning my A/F ratios with changes in my MAF tube diameters. I think I have it pretty much set now...Long term fuel trims are still at "0" correction after almost 200 miles.. __________________ Steal my car! (SOLD)...Now Porsche Cayman S Oil Cooler DIY: Here!

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09-13-2009, 07:58 AM	#4 (permalink)
Denny McLain Enthusiast Member Join Date: Feb 2009 Location: Double Oak Tx Posts: 255 Drives: 370Z, 96CE hotrod Rep Power: 18	[QUOTE=Modshack;195852]Understand...When I saw how limited the Cobb was I decided that was $6-700 I didn't need to spend...at least now. I've been tuning my A/F ratios with changes in my MAF tube diameters. I think I have it pretty much set now...Long term fuel trims are still at "0" correction after almost 200 miles.. QUOTE] Very interesting concept however an issue I see is the factory fuel curve is not linear. The same progression on every wideband readout I've seen. The cars are leaner at lower rpm getting progressively richer at higher rpm's. Mine's pulling out additional timing beginning right at 5000 rpm (as low as 17 and 18 degrees timing) which is killing the torque peak. In looking at the dyno wideband readouts, Cobbs AFR readouts (which aren't accurate btw), discussing this with Calvin At Cobb whom originally tuned the car, it appears the car might be a little lean under 5000 rpm which may be causing it to pull timing. It also might be the temps? Added fuel under 5000 and pulled some over 7000. (which shows 25-27 degrees of timing depending upon the temps) To do true fine tuning, you need to get into the MAF tables and hone on specific rpm's with the Cobb software as the fuel tables are pretty course. Biggest tuning issue and something I've never run into is when you make changes to AFR, you see it on the 02 readouts, but the car does not immediately respond on the dyno. This is a tremendous source of frustration as it's a place I've never been before, don't know why or what to do about it.

09-13-2009, 04:42 PM	#6 (permalink)
Denny McLain Enthusiast Member Join Date: Feb 2009 Location: Double Oak Tx Posts: 255 Drives: 370Z, 96CE hotrod Rep Power: 18	Works for everybody. Adding high flow cats leaned mine some also. Again, something I've not played with as I've gotten away from ported or Billet MAF's after finding out most of the local tuners preferred the stock MAF's. Certainly something to digest and think about. Speaking of something to think about and digesting.... Yesterday again checked intake temps on pretty much a standard stop and go route (to my health club to workout) taking the back way to avoid as much traffic as possible. About four or five lights, depends upon luck on how you hit them, however with a few stop signs in the interim. Key is standard route. The intake temps basically ran 12 degrees over ambient going down to about 10 during open throttle in 72 degree ambient and some light rain. This was 4 degrees hotter than the day before. Same route, slightly different conditions.???? OK....rainy days, Sundays, and high temps gets me down. Air dirverter picture by dennylmclain - Photobucket Small air diverter pop-riveted to underneath bumper. (Way to small, just trying be conservative) Sections removed from bumper picture by dennylmclain - Photobucket Removed bumper and removed two 2.5" thick sections directly below the filters. 3/4" of opening removed picture by dennylmclain - Photobucket Removed 3/4" of the rear area of the openings creating a gap. (top three middle sections of the front facade) Open front access to filters picture by dennylmclain - Photobucket A good two inch thick and six inch wide straight shot to the filters so they don't have to pull air from behind and the fans pull air to them. Who would know? picture by dennylmclain - Photobucket Looks untouched. What happens in Vegas, stays in Vegas and now you know how the magic trick is done. Same route, same conditions as yesterday: The car drove 7 degrees over ambient going down to 4-5 degrees during open throttle. 20 minute drive to health club, 187 water temps and let the car idle for 3-4 minutes. The most it got up to was 93 degree intake temp or 21 over ambient. On the way home after a 45-50 minute workout: 93 degree initial intake temp, went down to 82 driving temp within a mile and 80 WOT. Went to 8 and 6 over by the time I made it home with hot engine. Simpler for me than routing tubing and seems to help some. Next move is a larger air diverter and isolating the rear of the filters some from the radiator.